Improving grindability and bioaccessibility of chicken bone by in situ steam explosion

The impacts of in situ steam explosion (ISE) on the particle size, protein solubility and digestibility, calcium release and structural characteristics of chicken bone powder were analysed. ISE significantly reduced the average particle size from 142.62 to 84.47-105.10 mu m, while maintained the proximate compositions. The Fourier transforms infrared spectra and X-ray diffraction further illustrated that there were no marked differences in the functional groups between native and ISE bone powders. Moreover, soluble protein content in chicken bone powder was remarkably enhanced by the ISE from 3.28 to 3.73 mg g(-1). ISE powder (at 121 degrees C for 90 min) had higher protein digestibility (48.63%) than that of native (30.82%). Finally, ISE powder showed a higher calcium release and 2,2 '-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activity of digestive juice. The results proposed the feasibility of using ISE as an effective strategy to improve the nutritional quality of chicken bone.